Search

Amaç: Bu çalışmada heminle indüklenen ve indüklenmeyen K562 hücrelerinde siklik AMP düzeylerinin incelenmesi planlandı. Gereç ve Yöntemler: K562 hücreleri % 10 fetal dana serumu, 100 IU/ml penisilin, 100 Mg/ml streptomisin, 25 Mg/ml amfoterisin B ve 2 mM L-glutamin içeren RPMI-1640 içerisinde ve nemli % 5' lik karbondioksit etüvünde, 37 ºC' da çoğaltıldı. Çoğaltılan bu hücrelerde Tripan mavisi boyama canlılık testi yapıldı. Hemin ile muamele edilen (deney grubu) ve hemin ile muamele edilmeyen (kontrol grubu) hücrelerden birinci günden itibaren altıncı güne kadar hücre peletleri elde edildi. Elde edilen bu hücre peletlerinde siklik AMP konsantrasyonları, siklik AMP Enzim ‹mmuno Analiz sistemi kullanılarak ölçüldü. Tüm veriler Student's t-testi' ni takiben tek-yol ANOVA ile istatistiksel olarak analiz edildi. Bulgular: K562 hücrelerinin heminle muamelesi, hücre çoğalmasının baskılanmasına neden olmuştur. Heminle muamele edilen K562 hücrelerinin çoğalmasına rağmen siklik AMP düzeyleri zamana bağlı olarak azalmıştır. Heminle indüklenen K562 hücrelerinin hücre içi siklik AMP düzeyleri azalırken, kontrol hücrelerinin siklik AMP düzeyleri kararlı kalmıştır. Sonuç: Bu sonuçlara dayanarak, diğer eritroid indükleyiciler veya hemin ile muamele edilen K562 hücrelerinde siklik AMP düzeylerinin hangi mekanizmayla düzenlendiğini anlamak için daha çok bilgiye gerek vardır., Objective: This study investigated the intracellular cyclic AMP concentrations in hemin-induced and uninduced K562 cell line. Method: K562 cell line were grown in RPMI medium supplemented with 10% fetal calf serum (FCS), 100 IU/ml penicillin, 100 Ìg/ml streptomycin, 25 Ìg/ml amphotericin B and 2 mM L-glutamin at 37 ºC in humidified air containing 5% CO2. A Trypan blue stain viability test was performed for produced K562 cells, and those used to obtain cell pellets from 1 day to 6 day, under the the following conditions: without hemin treatment as a control group and with hemin treatment as an experimental group. All data were statistically analyzed using one-way ANOVA, followed by Student`s t-test. Results: Treatment of K562 cells with hemin leads to inhibition of cell proliferation. Cyclic AMP levels of K562 cells that were treated with hemin are decreased in a time dependent manner, although the hemin-induced cells are proliferated. Intracellular cyclic AMP levels of hemininduced K562 cells decreased, while the control cells had stable cyclic AMP concentrations. Conclusion: On the basis of these results, it is recommended that further data collection is needed to analyze the mechanism by which intracellular cyclic AMP levels are regulated in K562 cells treated with hemin or other erythroid inducers.

WOS: 000254852500007, Heterotrimeric G proteins, commonly known as G proteins are members of the large GTPase superfamily that are conserved from bacteria to mammals. G proteins play an essential role in cellular signaling by coupling many cell surface receptors to effectors on the plasma membrane. G proteins are composed of an alpha-subunit that binds and hydrolyzes GTP and a beta gamma-subunit complex. To date over 20 different a subunits, 5 beta subunits and 14 gamma subtypes have been defined. Classification of G protein heterotrimers are based on the primary sequences of their alpha-subunits, resulting in four main families. In its inactive state, each G protein is a heterotimer in which the GDP bound alpha chain is tightly associated with the beta gamma subunits. Receptor activation promotes the replacement of GDP by GTP and the consequent dissociation of a from beta gamma. Both alpha GTP and the beta gamma complex interact with and regulate specific effectors. Activation is then terminated by the intrinsic GTPase activity of the a chain, which returns the protein to its inactive state. G proteins are regulated by posttranslational modifications including phosphorylation, myristoylation, palmitoylation, and prenylation of G alpha- and G beta gamma- subunits. G protein alpha- and beta gamma- subunits regulate the activities of diverse effectors. G proteins mediate a wide variety of cellular responses, including sensory perception, neuronal activity and hormonal regulation. Recent reports indicate that GPCRs and G proteins are also involved in the regulation of cell growth, differentiation and cellular transformation.